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Television/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby A man, Tim, is looking at an array of six television screens. Each shows the same picture of a man wearing a hat. Tim appears to be mesmerized by the scene. A robot, Moby, comes into view. Moby has three blue lights on his chest. Tim is wearing a white T-shirt with an image in the center consisting of seven vertical bars with different colors. In the background, we can see rows of washing machines and rows of computers. Moby waves his arm up and down in front of Tim’s face, but Tim’s expression does not change. TIM: They’re… so…beautiful. Tim reads from a typed letter. TIM: Dear Tim and Moby, My parents want to buy a new UpperWord T V. What kind should they get? Thanks, Sally. MOBY: Beep! Moby points at a television with a very deep picture tube. TIM: No way, those are so 1998. These TVs make images with a device called a cathode-ray tube, or UpperWord C R T. A side view of the television with the deep picture tube is shown. An animation shows the interior of the device. An electronic device in the back is labeled “cathode” and displays with a symbol of electronic waves. Dotted lines come out one end and pass through several lenses to get to the screen in the front. The caption reads: “cathode-ray tube (UpperWord C R T) TIM: Flat-screen TVs use liquid crystal or plasma displays. Tim points at two televisions with identical pictures of the man with the hat. One is labeled “UpperWord L C D” and the other is labeled “plasma.” MOBY: Beep. TIM: No matter how a UpperWord T V creates its images, it all starts with an electronic signal. A drawing shows a television set with an indoor antenna. The image on the screen shows a man walking in a space suit with mountains in the background. In the sky, there are two moons. TIM: Some TVs have antennas that pick up signals broadcast from a transmitter — just like a radio. The television set moves to the bottom left portion of the screen. At the top right, a tall tower appears. Circles radiate from the top of the tower. TIM: But these days, most UpperWord T V’s receive their signal from a wire that runs into your house, or a satellite antenna that receives signals beamed from space. A new image shows the same television set but without the antenna. An insert shows a coaxial cable. To its left, another television is shown with a wire going to a dish antenna. An insert shows a satellite in space radiating a signal toward the Earth. The view switches back to Tim and Moby. TIM: Anyway, once a UpperWord T V receives the signal, it interprets the information to make the picture on the screen. MOBY: Beep? TIM: Well, it depends on the type of UpperWord T V. In a UpperWord C R T UpperWord T V, a device called a chrominance decoder splits the signal into three colors that form the picture: red, green, and blue. An animation shows a rectangular gray box labeled “chrominance decoder.” A black wire enters it from the left. A sinusoidal signal can be seen drawn in the wire. Coming out of the right side of the box are three wires. One is red, one is green, and one is blue. TIM: The three signals go to the cathode, a heated filament, kind of like the one inside a light bulb. The animation pans to the right following the three colored wires. They go into the rear of an object shaped like a television set and end at three rectangles, colored red, green, and blue, respectively. A caption reads: “cathode.” TIM: Guided by an electromagnetic field, three beams of electrons stream off the heated cathode. The animation shows three beams extending from the front end of each of the three colored rectangles. The beams end at the front of the television screen. The beams dance around in different directions. TIM: The inside of the TV screen is coated with stripes or dots of phosphors, substances that emit light when they absorb energy. An image on the screen is filled with groups of three vertical ovals all neatly lined up in rows and columns. In each triple, one oval is red, one is green, and one is blue. A close up shows one of these triples. A caption reads: “phosphors.” TIM: One electron beam hits only red phosphors; one hits the blue phosphors; and one hits the green phosphors. The animation shows a beam hitting the red oval. It lights up a bright red. Another beam hits the blue oval. It lights up a bright blue. Then a third beam hits the green oval and it lights up a bright green. TIM: Combinations of lit phosphors can create colors other than red, green, and blue on your screen. The view shifts to Moby. Moby is holding three transparencies, colored red, green, and blue, respectively. As Moby moves the three transparencies around, you can see different colors when you look through more than one transparency at a time. For example, where the red transparency overlaps the blue transparency, the overlapped region appears to be purple. MOBY: Beep? TIM: Right, these flat screens are skinny because they don’t use long cathode-ray tubes. Tim and Moby move over to another part of the department store. In the background can be seen a display case filled with flip phones that are flipped open so that you can see a small flat screen on the upper half and a keyboard on the lower half. TIM: Instead of a beam of electrons, this liquid crystal display — or UpperWord L C D — TV uses a backlight. The animation changes to show a large flat screen display. Looking behind the screen, we see a layer consisting of horizontal stripes. Behind that is a layer of vertical stripes. Behind that is a solid white layer labeled “backlight.” A caption reads: “liquid crystal display (UpperWord L C D). TIM: That’s a very bright light source located at the back of the UpperWord T V. The view switches back to Tim and Moby. TIM: On its own, the backlight can’t create any images; it’s just a big light that’s either on or off. Watching that wouldn’t be much fun. To create an image, some of the light has to be blocked out, or dimmed. The view changes to a flat-screen television, labeled “UpperWord L C D.” showing a black and white image of the man wearing the hat. The man’s mouth is moving. TIM: First, the light waves are filtered so they’re all moving along the same path. The view shifts back to the solid white layer. Three arrows of light can be seen coming off this layer and moving in three different directions. The arrows go through the layer with vertical stripes and come out the other side all moving in the same direction. TIM: Then the light has to pass through another filter. In order to do so, the light waves have to be twisted 90 degrees. The arrows pass through the layer with horizontal stripes. The arrows are drawn to appear to be three-dimensional. Upon going in to this layer, the body of each arrow is vertical. Upon leaving the layer, the body of each arrow is horizontal. TIM: That’s where liquid crystal molecules come in! A close-up of the first filter shows that it is made of a bunch of vertical rods. A caption reads: “liquid crystal molecules.” TIM: A whole bunch of these rod-shaped molecules are sandwiched between the filters. The crystals line up with whichever filter they’re closest to, making a helix shape— kind of like a strand of UpperWord D N A. The animation shows the rods formed in a helical pattern. TIM: In this natural state, the crystals act like a tunnel for light, gradually twisting the waves so that they can pass through the second filter. The animation shows that the second filter consists of narrow horizontal slits. In order for the light waves to get through, they must twist to become horizontal so that they can pass through the slits. TIM: The crystal tunnel untwists when it’s zapped by an electric current — which happens when you turn on the UpperWord T V. The animation shows the crystals starting in a helical state and then untwisting to become a set of parallel rods all in a single plane. A flash of light occurs. An insert shows a finger pressing the “on” button of a television. TIM: The stronger the current, the more the tunnel untwists — and the more it untwists, the less light gets through. The scene switches to a view of Moby sitting on a couch watching television holding a box of popcorn. On the left side of the screen we see light passing through the various filters. On the television screen, we see the man with the hat. At the top of the screen is a small box with a lightning bolt on the left and roads of increasing size moving to the right. As the rods untwist, the picture gets darker and darker. When the rods are all perfectly parallel, the picture becomes completely black. TIM: The display creates shadows by applying different amounts of electricity to different parts of the screen. Finally, red, green, and blue filters color the light that makes it through. The scene switches to Tim talking to Moby in front of the washing machines. A large square fills the screen with three vertical stripes: red, green, and blue. TIM: The area covered by just one of these filters is called a subpixel, and three of them together make a pixel. The blue stripe is highlighted and a caption reads: “subpixel.” Then all three stripes are highlighted and the caption reads: “pixel.” TIM: UpperWord L C D Upper Word T V’s display images by manipulating the color and brightness of millions of pixels at the same time! A large view of the television picture of the man in the hat appears. An insert points at one small spot on the man’s hat and blows it up to show that it actually consists of a large number of red, green, and blue stripes. MOBY: Beep! The scene shifts back to Tim and Moby. TIM: Well, plasma displays are a little different. Instead of liquid crystal molecules between the glass plates, they have millions of tiny cells filled with a mixture of gases. An animation shows an array of cells filled with gas. TIM: An electrified grid crisscrosses the cells in front and back. The animation shows three grids, one in front with horizontal lines, one in the middle that is all gray, and one in back with vertical lines. They all move together to form one square with horizontal and vertical lines. TIM: When the grid is charged with electricity, the gases in the cells are ionized, or charged. Ionized gas is also called plasma. A close-up of one cell is shown. The grid flashes and the cell then lights up. TIM: The plasma inside these TVs releases ultraviolet light invisible to our eyes. The scene shifts back to Tim speaking. TIM: But the back wall of each cell is coated with a red, green, or blue phosphor - the same substances that make light in cathode-ray-tube UpperWord T V’s! The grid of cells is shown again. This time, they are organized into columns of the same color: with the colors being red, green, and blue in succession. TIM: When they absorb the ultraviolet rays, the phosphors give off light. Three of these cells together form a pixel. The animation shows some of the cells getting brighter. The scene zooms in to show two sets of three cells. In each set, one is green, one is blue, and one is red. TIM: Just like UpperWord L C D UpperWord T V’s, plasma UpperWord T V’s create images by controlling the color and brightness of millions of pixels. An animation shows two televisions side by side. One is labeled “plasma” and the other is labeled “UpperWord L C D.” Both show the same image of the man with the hat. The scene shifts to Moby who is watching a television screen labeled “the biggest UpperWord T V ever!” MOBY: Beep! Tim walks over to Moby and looks at the huge screen. TIM: Um, I think that one’s a little big for my bedroom. The scene shifts to Tim’s bedroom. Both Tim and Moby are sitting cross-legged on the bed staring toward the viewer. A television laugh track can be heard in the background. Moby has a frown on his face. MOBY: Beep. The view changes and we can now see the very small television. A quiz show appears to be displaying. The television set is nestled on a book shelf between two books. The screen is square-shaped and the height is about the same height as one of the books. TIM: Look, it was all I could afford, okay? Category:BrainPOP Transcripts